Means for feeding and mixing powdered coal and air



W. R. FIELD.

MEANS FOR FEEDING AND MIXING POWDERED COAL AND AIR.

APPLICATION m50 MAH-15,1920.

1,410,246. l tented Mar. 2L 1922.

2 SHEETS-SHEET I.

W. R. FIELD.

MEANS FOR FEEDING AND MIXING POWDEHED COAL AND AIR.

APPLICATION FILED MAH. I5. 1920.

lfll. atented Mar. 21, 1922.

2 SHILEISHSHEET 2.

UNITED STATES PATENT oFFlcE.

WILLIAM YIt. FIELD, OF DECATUR, ILLINOIS.

Specification of Letters Patent.

Patented Mar. 21, 1922.

Application led March 15, 1920. Serial No. 366,101.

To all who/m. 'it may concern.'

Be it known that I, WILLIAM R. FIELD, a citizen' of the United States, residin at Decatur, in the county of Macon and tate of Illinois, have invented certain new and useful Improvements in Means for Feeding and Mixing Powdered Coal and Air, of whlch the followin is a specification, reference being hadto tie accompanying drawings.

This invention relates to devices for feed-y ing powdered coal or other owdered materials, and particularly to a eeder for feeding atomized coa-l, that is very finely powdered coal, and mixing this coal with a1r so as to secure perfect combustion of the coal when it is projected into a combustion chamber.

One of the main difliculties in the use of finely powdered coal or like material as a fuel for furnaces is the difliculty of handling the nely powdered coal. This is due to the fact that a mass of finely powdered material will not follow irregular shapes, as for instance, irregular piping, and thatv it is very difficult to discharge from a container, spout or other holding device having an outlet smaller than the largest diameter of the container or holder itself. A small portion of the mass will ow out the relatively small opening, but when this small portion has passed through the opening, the remainder of the powdered mass will remain within the container.

The general object of my invention is to provide impved means for feeding powdered materials, and particularly powdered coal, which means is so constructed that a barrel or container may be disposed i-n an inverted osition over the feedin device and the coal fed therefrom finely an in required mass, and when the container is empty it may be removed from the to of the feeding device and a new container p aced thereon.

A further .object is to provide a mechanism of this character in which the finely powdered coal, after being fed from the container, is mingled with air, either preheated air or cold air, and is then thoroughly mixed with the air so as ,to provide for properv carf buration of the coal, and then is discharged by an air blast through a discharge pipe.

And a further Objectis to provide means whereby the amount of coal which is fed may be controlled.

A further object is to rovide means whereby in the action of mixing the powdered coal with the air, the Vmixture of air -and coal is thrown outward by a revolving fan and thus expanded, then drawn centrally to bring the particles into intima-te contiguity, then thrown outward to expand it, then again drawn centrally and discharged.

A further object is to provide means whereby a relatively large amount of air may be drawn into the feeding device in proportion to the powdered coal.

A further object is to provide means whereby an amount of coal in proportion to the slze of the fire required may be fed from ythe machine by varying the speed of the revolving fans used therein.

Other objects will appear in the course of the following description.

My invention is 'illustrated in the accompanying drawings, wherein e Figure 1 is an elevation partly in section of a coalrfeeder and carbureter constructed in accordance with my invention;

Figure 2 is a section on the line 2--2 'of Figure l;

Figure 3 is a top plan view ofthe damper plate 26; v

Figure 4 is a section on the line 4-4 of Figure 1;

Figure 5 is a top plan view of one of the rotatable fans.

Referring to these drawings, 10 designates a cylindrical air chamber which may be made of sheet metal or other suitable material, and which at its lower end is connected to an annular casing 11, the two sections 10 and 11 being held together bybolts 12, and the section 11 being supported by legs 13. The air chamber or section 10 formed with means for admitting air to the linterior of the chamber by air opening, for instance, one of which is indicated at 10a in Figure 1 and the air chamber or section 10 at its upper end is ianged, as at 14, and provided with spring latches 15, these spring latches being adapted to engage over the flange 16 of a barrel, container vor magazine17 in-v tended to hold the coal in very finely powdered form. The flange 14 forms a seat for the end of the inverted container 17, and

' and 33. The disks 30 and 32 carry up the springs 15 or other latches hold the inverted container in place upon the wall of the chamber 10.

Disposed within the chamber 10 is a coal receiving pan, designated 18. This chamber is smaller in diameter than the chamber 10 and the wall thereof extends up to the-top of the chamber 10. This pan rests upon supporting brackets 19 and extends up over the top of the casing l0 so that the pan maybe lifted out when a container 17 is changed. Disposed centrally of the pan 18 is a conical spreader 20 having its apex disposed upwardly and supported by brackets 21 extending inward from the wall of the pan. The lower end of the pan is closed by a plate 22 whose outer margin lis formed with a.

plurality -of perforations23. This plate 22 is spaced from the lower edge of the cone or spreader 20, and operating in this space are a plurality of blades 24 attached to a shaft 25 driven as will be hereafter described. These 'blades act to feed the coal down through these apertures 23 and to break up any adhesion of the coal so that the coall will constantly fall through these apertures 23. Disposed preferably below the plate 22 is an annular damper 26 having perforations y27 through it which register with the perforations 23, and this annular plate consti# tutes means for controlling" the outflow of coal through thc perforations 23, this plate having means vt hereby it may be` shifted to more or less clrse the passage through the perforations 23 and thus control the feed of` coal. Attached to the brackets 19 'is a' hopper 28 which receives coal discharged through the perforations 23 and 27, and disposed within the upper portion of this hopper and supportd in any suitable manner, as by attachment to the plate 22, is a circular housing 29 forming a gear case.

The section 11` supports within it a pluthe blades 36, which blades are illustrated asj curved. It will be obvious from the drawing that one of the rotatable fans or disks and one of the fixed disks with its'fixed blades operate together and within a chamber, and

it will also be seen that both of these'disks 31 and 33 have relatively large central apertures; Thehopper 28 discharges through Maaate the central aperture of a bottom plate 37 which closes the lower end of the chamber 10, this plate 37 extending nearly to but not touching the lower end of the hopper 28 so as to leave an annular port 38 through which air may pass, while the coal will. pass downward through the hopper 28. Extending from the central aperture in the plate 33 is a discharge pipe 39.

F or the purposeof driving the rotatabler fans constituted by the disk 30 and the blades 34 and for rotating the blades 24, I

the housing 29. Carried upon the shaft is` l a pinion 41 which engages with a relatively large gear wheel 42 in the housing, which in turn carries a relativelyl small pinion 43, and this'meshes with a relatively large gear wheel 44 looseon the'shaft and carrying a stud shaft upon which the blades 24 are mounted. Thus the blades are rotated at a relatively slow speed in comparison with the speed of rotation of the disks and fan blades 30 and 34 or 32 and 34. This permits the fan to turn very much faster than the coal is fed -in order,v to have the proper amount of air necessary for instant combustion. The housing 29, of course, forms means whereby the reducing gearing shown may run in oil and whereby this gearing is thoroughly protected from the intrusion of coaldust or other foreign matter into the housing.

I have illustrated an electric motor 45 mounted upon the lower portion of the machine and engaged with the shaft 40, but I do not wish to be limited to this, as other means might be used for driving the shaft 40, and power may be secured in any desired manner. Preferably the motor, whatever its form, is a variable speed motor so that the fans may be run at variable speeds so as to provide for a large or a small lire as reuquired at any time, thus making the feeding device flexible and elicient. It is obvious that the feeding device may be made in any size `suitable for large and small heating plants or for the very largest o'f power plants. f

The operation of this mechanism will be evident from what has gone before. The

magazine, barrel or other container 17k is inverted over the top of the feeding device and the spreader20 causes the coal or other powder to feed downward to the rextremities of the blades 24 vand these blades force the powder to pass through the perforations 1 23 andbe discharged onto the hopper 28, by which the powder is dischar ed in the center of the rotating set of fan b ades carried by 31 of the series, and from thence the mingled` coal and air pass downward into the suction fan and are again projected violently outward against the wall of the fan casing and forced through the space between the blades of theA 'fourth bladed element 33, and thence out through the discharge pipe 39. When 'the mixed coal and air are thrown outward by the blades 34, the mixture is expanded, and while being drawn through or forced between the stationary or fixed blades 36, the mixture is contracted, and thus by alternately expanding and contracting the mixture and forcing the air and coal through relatively small spaces, the air is thoroughly intermingled with the coal dust or powder and is discharged into the pipe 39 and from the pipe 39 ready for instant combustion.

It will be seen that the ratio of the speed of the blades 24 to the rotating fans is kept constant at all times so that the proportion of air and coal is kept at all times the same, that is, of course, the proportion of coal and air may be varied by shifting the annular member 26, but whn'this' member has been adjusted, the' ratio between the air and coal remains the same until a new adjustment of the damper 26 is made.

In taking the coal from the outside edge of the container or barrel all around' the spreader 20, the fuel will descend under its own weight and will not clog, and the weight of the coal is supported by means of the spreader 20 so that the weight of this coal does not affect or prevent the rotation of the blades 24. Only the ends of the blades meet with resistance in the coaland thus the cost of power required to rotate the blades 24 is very materially reduced.

Itis to be noted that the disks 32 with the fan blades 34 and their peripheral discharge and the disks 31 with their radiating blades f 36 and the central discharge .form a series of chambers having substantially4 radial partitions, the alternate chambers having a peripheral discharge to the next successive chamber and the intermediate chambers having a central discharge to the next successive chamber, and that the coal and air as-it is drawn through theimachine is alternately' expanded in bulk and compressed in bulk. Thus it passes into the rst fan of the series at the'center thereof and moves outward in radial spaces which increase in size. The coal and air moves downward then into 'spaces gradually decreased in size toward the center and from thence the'coal and air are discharged into chambers which gradually increase in sizel outward and soon, thus securing a thorough mixing of the-coal and air prior to its discharge rom the machine.

It will be seen that my invention is very simple, that the coal is thoroughly intermingled with the air and placed in the best possible condition for combustion, and that iunasmuch as all the parts are enclosed, there is no chance for the coal dust toblow out of the mechanism and contaminate adjacent objects.

When it is desired to invert a container 17 v upon the casing 10, the pan 18 is lifted out, the' shaft 40 sliding through the gear wheels in the gear case 29 and placed upon the top of the new container and then the container inverted into place on the casing 10. The

.upper end of the pan 18 is outwardly flared as shown in Figure v1, or otherwise forme so as to lit the open end of the container 17 so that this pan with the hopper 20 may be placed upon the container 17 before it is infv verted and then the container invertedand set upon the casing 10. ,n

While I have before referred to this device as being particularly used for the purpose of feeding coal, yet it is to be understood that itvmlght be used for the purpose ,of feeding other powdered materials, and I do not wish to be limited to its use in connection with a furnace or for feeding any particular kind of powdered materialw I have illustrated it as a means for feeding coal and providing air for the proper combustion of the coal for the reason that thisdevice is particularly adapted for this purpose.

I claim 1. A mechanism of the character described including a container, a housing disposed below and supporting the container, a an disposed in said housing below the container and open at its upper end, the bottom of the pan being formed adjacent its circumference with outlet apertures, "lblades "mounted within the pan and passing over said apertures, an inverted conical spreader disposed within the pan and having its apex upward and disposed above the blades, and means for rotating said bla des, a hopper into which the powdered materiall discharges through the apertures in the bottom of the pan, and means for pneumatically withdrawing the powdered material from thelower end of the hopper. v'

2. A mechanism of the character described including a container, a housing disposed below and supporting the container, a pan* disposed in said housing below the container and open at its-upper end,` the bottom of the pan being formed adjacent its circumference with outlet apertures, blades mountposed within the pan and havin its aen upward and disposed above t e bla es, means for rotating said blades, a hopper into which the powdered material discharges through the apertures in the bottom of the pan, means for pneumatically withdrawing the powdered material from the lower end of the hopper, and means for mixing the material so withdrawn with air.

3. A mechanism for mixing air and finely powdered coal including a plurality of rotatable, bladed fans, each disposed in a housing and ejecting the material outward against the wall of the housing, a plurality of elements having blades directed centrally, said elements being disposed alternately with respect to the fans, the fans discharging at their periphcries onto the peripheries of the elements and each of said elements having a central opening, means for rotating said fans, means for feeding air and coal to the central portion of the first fan of the series, and a discharge pipe leading from the central opening of the last element of the series.

4. A mechanism for feeding and mixing powdered coal and air includmg a housing formed to provide a series of chambers, each chamber having substantially radial parti tions, alternate chambers having a periph-1 eral discharge to the next adjacent chamber and intermediate chambers having a central discharge to the next adjacent chamber, and means for causing the air and pow- 4 dered coal to pass successively through the several chambers.

5. A mechanism for feeding and mixing powdered coal and air including-a housing, pneumatic means for drawing air and powdered coal into said housing, a series of fans disposed within the housing in spaced relation to each other and discharging outward toward the wall of the housing, a series. of chambers disposed between said fans and having radiating partitions, the central portion of each chamber havingv an vaperture discharging into the central portion of the next succeedinffan.

6. A mechanism for feeding and mixing powdered coal with air comprising a pan having'feeding openings, a container discharging into said pan, a hopper into which the feeding openings of the vpan discharge, an air chamber surrounding the hopper, a fan mounted below the hopper and air chamber and into the central portion of which the hopper and air chamber discharge, said fan having` blades discharging outward, an element vmounted below the first named fan and 4having radiating blades `leading to a central opening, the coal and air being discharged by the iirst named 'fan 'into the space between said blades, and a discharge pipe in which material from the said element is discharged.

andere an air chamber surrounding the hopper, a

rotatable fan mounted below the hopper and air chamber and into the central portion of which the hopper and air chamber discharge, said fan having blades discharging outward, an element mounted below the said fan and having radiating blades leading to a central opening, the coal and air being discharged by the said fan into the space between said blades, a second fan having blades disposed below the said element and discharging outward and receiving material from the centervof the iirstnamed element, and a second fixed element having hired, radially extending blades into which the second named fan discharges and having a central aperture and a discharge pipe connected to said central aperture, and means for rotating said fans..

8. A mechanism for feeding and mixing powdered coal with air including a pan, a magazine discharging into the pan, a spreader carried within the pan and causing the feeding of the coal toward the periphery of the pan, the bottom of the pan at its periphery having discharge openings, a rotatable feeding mechanism mounted upon the bottom of the pan and operating said discharge openings and befnleath the spreader, a hopper disposed below the pan and receiving material through the discharge openings thereof, an air chamberV surrounding the hopper, acasing disposed beneath theI air chamber and containing a plurality of fans, one set of fans being fixed and the other set rotatable, the lowermost rotatable fan having a central aperture into which the hopper vand the air chamber discharge and having outwardly curved blades, the lixed'fan hav- ,ing radially extending blades, the rotatable below the fixed fan and receiving material at its center from said fixed. fan and discharging at its periphery, and a second fixed fan havmg radial blades receiving material at its periphery and discharging at its cenw ter, a discharge pipe leading from the' second named fixed fan, and means forrotating the feeding blades and the rotatable fans at relatively different speeds.

. 9. A mechanism for feeding and mixing 'powdered coal with air including a pan, a

magazine discharging into the pan, l a spreader carried within the pan and causing the feeding of the coal toward the periphery of the pan, the bottom of the pan at its pe' riphery having discharge openings, a rotatable feeding mechanism mounted upon the bottom of the pan and operating said lao I discharge openings and beneath the spreader,

cio

a hopper` disposed below, the pan and receivinglmaterial through the discharge openings t ereof, an air chamber surrounding the hopper, a casing disposed beneath the air chamber and containing a plurality of fans, one set of fans being fixed and the other set rotatable, the 'lowermost rotatable fan having a central aperture into which the hopper and the air chamber discharge and having outwardly curved blades, the fixed fan having radially extending blades, the rotatable fan discharging onto the periphery 'of the fixed fan, a second rotatable fan disposed below the fixed fan and receiving material at its center from said fixed fan and discharging at its periphery, a second fixed fan having radial blades receiving material at its periphery and discharging at its center, a discharge pipe leading from the second named fixed fan, and means for rotating the feeding blades at a speed slow relaive'tothe speed of rotation of the rotatable ans.

l0. A mechanism for feeding and mixing powdered coal with air including a pan, a ma azine discharging into the pan, a sprea er carried within the pan and causingthe feeding of the coal toward the periphery of the pan, the bottom of the pan at its periphery having discharge openings, a rotatable feeding mechanism mounted upon the bottom of the pan and operating said discharge openings and beneath the s reader, ahopper disposed below the ari ancireceiving material through the disc arge openings thereof, an air chamber surrounding the hopper, a casing disposed beneath the air chamber and containing a plurality of fans, one set of fans being-xed and the other set rotatable, the lowermost rotatable fan discharging onto the periphery of the fixed fan, a second rotatable fan disposed below the fixed fan and receiving material at its center from said fixed fan and discharging at its periphery, a second fixed fan having radial blades receiving material at its a riphery and discharging at its center, aV ischar e pipe leading from the second named fixe fan, and means for rotating the feeding blades at a speed slow relative to the' speed of rotation of the rotatable fans, said means comprising a shaft. passing upward through the fan housing and through the hopper, the rotatable fans bein attached to said shaft and driven direct y thereby, reducing gearin transmitting power from said shaft to t e feeding blades, and a housin enclosing said reducing gearing.

11. mechanism for eedin and mixing `powdered coal with air inclu ing a pan, a magazine discharging into the spreader carried within `the pan an an, a causing'the', feeding of the coal toward the periphery of the pan, the bottom of the pan at its periphery having discharge openings, a rotatable feeding mechanism mounted upon the bottom of the pan and operating said discharge openings and beneath the spreader, a hopper disposed below the pan and receiving material through the discharge openings thereof, an air chamberV surrounding the hopper, a casing disposed beneath the air chamber and containing a plurality of fans, one set of fans being fixed and the other set rotatable, the lowermost rotatable fan discharging onto the peripher of the fixed fan, a second rotatable fan dlsposed below the fixed fan and receiving material at its center from said fixed fan and discharging at its periphery, a second fixed fan having radial blades receiving material at its periphery and discharging at its center, a discharge pipe leading from the second named fixed fan, and means for rotating the feeding blades at a speed slow relative to the speed of rotation of the rotatable, fans, said means comprising a shaft passing upward through the fan housing and through the hopper, the rotatable fans being attached to said shaft and driven directly thereby, reducing gearing transmitting power from said shaft to the feeding blades, and a housing enclosing said reducing gearing, said housing being disposed within the hopper and attached to the bottom of the feeding pan. 12. A mechanism for feeding and mixing powdered coal with air including a housing, a fan mounted within the housing, means for discharging coal and air into the central portion of the fan, said fan having blades discharging outward, an element mounted below the fan and havingpradiat- 'ing blades leadingy to a central opening, the coal and air being, discharged by the fan into the space between said blades, and a discharge pipe leading from the center of said element and into which material is discharged;

13. A mechanism for feeding and mixing powdered coal with air including a rotatable fan having blades' discharging outward, means for feeding mixed coal and air to the center of said fan, an element mounted below the fan and having radiating blades leading to a central openin the coal and air being discharged from t e fan into the space between said blades, a second rotatable fan having blades disposed below the said element and discharglng outward and re ceiving material from the center of said element, and a second fixed element having fixed, outwardly divergent blades into which the second named fan discharges and hav-l ,.fi-ng a central aperture, a' discharge pipe con- 14. A mechanism' for feeding and mixing powdered coal and air including a series of outwardly discharging fans, means for diS- charging coal and air into the center of the I first fan of the series, means for Conducting the coal and air discharged from the periphery of each fan to .the center of the next succeeding fan, and a discharge pipe into which the final fan of the series operatively discharges. l0

In testimony whereof I hereunto affix my signature.

WILLIAM R. FIELD. 

